Electric switch and interlocking mechanism therefor



Aug. 17 1926.

' 1,596,513 C. D. AINSWQRTH ELECTRIC swn'cu AND INTERLOCKING MECHANISM'rnznar'on Filed August 1 4, 1923 u 2 Shoots-Shoot 1 Ira/621702- (LLA:0W

Aug. 17 1926.

c. o. AINSWORTH ELECTRIC SWITCH AND INTERLOCKING MECHANISI THEREFORFiled August) 14, 192:

2 Shoots-Shut 2 Patented Aug. 17, 1926.

' UNITED STATES PATENT OFFICE.

CENTER D. vAILWSWOR'FH, OF WOLLASTON, MASSACHUSETTS, ASSIGNOR, BY MESNEASSIGNMENTS, TO CONDIT ELECTRICAL MANUFACTURING CORPORATION, OF BOSTON,MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

ELECTRIC SWITCH AND ,INTERLOOKTNG MECHANISM THEREFOR.

Application med August 14, 1323. Serial No. 057,440.

This invention relates to electric switches and. particularly tointerlocking mechanism arranged to govern the order of operation of twoor more switches in a predetermined manner.

For the starting of induction motors, for instance, it is common toprovide two separate switch units, the operating handles of which may beplaced side by side and one of the switch units serves as a startingswitch and the other as a running switch. The switches are adapted to beoperated in sequence and the starting switch 18 adapted to beclosed'first to bring the motor upto 'speed and then opened and therunning switch is adapted immediately thereafter to be closed.

If the running switch is closed before the starting switch, or viceversa, or if both switches are closed simultaneously, damage may beincurred.

An object of this invention is to provide interlocking mechanismconnecting a plurality of switches and particularly startin'g andrunning switches, so arranged as to lock the running switch againstoperation until the starting switch has been closed and also so arrangedthat when the running switch is moved towards closed position thestarting switch is opened prior to the completion of the movement of therunning switch into switch-closed position.

A further object is the provision of means whereby the starting handlesof the switches are disconnected from the switch mechanism and are freeto move between open and closed positions without actuating the switcheswhen the switches are locked in open position.

A yet further object isthe provision of means by which the runningswitch may be opened manually through the interlocking mechanism andmeans to prevent the manual disabling of the interlocking means.

A further object is generally to improve the construction and operationof electric switches.

Fig. 1 is a plan view of two switch mechanisms, as starting and runningswitch mechanisms, especially adapted for induction motor control, andwith which my invention is incorporated.

Fig. 2 is a side elevation along line 22 of Fig. 1.

Fig. 3 isa side elevation along line 3.-3 of'Fig. 1.

Fig. 4 is a front elevation of the mechanism illustrated in Fig. 1, theoperating mit: the running switch mechanism to be closed.

Fig; 7 is a, perspective view of some of the. elements associated withthe interlocking mechanism.

Fig. 8 is a detail of the running switch mechanism illustrating :therelative. position of the parts to actuate the interlocking mechanismand strip the starting switch mechanism.

The invention is here shown applied to the switch operating mechanismdisclosed in my co-opending application, Serial No. 606,67 8, filedDecember 13, 1922.

As here shown, the switch mechanism includes a face plate 10 for thestarting switch and a second face plate 10 for the running switch. Saidface plates are adapted to support the switch operating and controllingmechanism and are or may be attached side by side to. a suitablesupporting structure. The face plates include the coil boxes 11 and 11within which are or may be enclosed suitable overload coils, not shown,and which are or may be ar ranged to actuate the tripping mechanism toopen the switchesupon overload. Said trippin'g'mechanism may include thetrip ping plates 13 and 13 which are or may be arranged to engage andraise latches hereinafter to be described, whereby to permit theswitches to move to open position.

The actuating mechanism for the switches may include the levers 14 and14 which are pivoted on pins 15 and 15 supported in the front walls ofthe respective coil boxes 11 and 11" of the face plates. Switchactuating rods 16 and 16 are pivotally connected to said levers 14 and14 at the upper ends thereof and extend rearwardly over the tops of thecoil boxes and under the tripping plates 13 and 13 and through the rearof the face plates for connection with the. immediate circuit-controlingelements, not shown, of the switches, in accordance with more or lesscommon practice.

A movement of said levers 14 and 14- inwardly or toward a verticalposition is arranged to effect the closing of the switches while amovement in the reverse direction or into a position as illustrated inFigs. 2 and 3 is arranged to effect the opening of the switches. Therespective bars forming said levers 1% and 14: are or may be connectedat their upper ends by pins 17 and 17 and latch rollers 18 and 18 may berotatably disposed on said pins between said bars. Switch actuatingmembers, as operating handles, are or may be provided; and said handlesmay comprise spaced bars 20 for the starting switch and similar bars 20for the running switch. Said bars are disposed on opposite sides of thelevers 14 and ll respectively and are or may be pivoted on said pins 15and 15 concentrically *ith said switch levers 1 1 and l t. Said handlesare adapted to be connected with said levers 14c and 1 h only by meansof latches which are under control of the tripping plates 13 and 13 andalso of the interlocking mechanism as will hereinafter be described. Forthis purpose, said operating handles are or may be formed or providedwith the rearwardly directed extensions 21 and 21 and latches 22 and 22may be pivoted to said extensions and be movable with said handles. Saidlatches are or may be formed or provided with forwardly-directed notchedportions 23 and 23 which, when the handles are moved outwardly or intoalignment with the levers 1a and 14 are adapted to engage with the latchrollers 18 and 18, whereby to connect said handles and leversreleasingly. The construction is or may be such that when said handlesare moved inwardly or toward a vertical position the levers let and 14sare or may be moved into corresponding positions whereby to close theswitch. The latches are adapted, also, to be so arranged that when thenotched portions thereof are depressed to clear the latch rollers, thelevers 1st and 1e are moved outwardly by the weight of the switchmechanisms, or by other means, to cause the switches to openindependently of corresponding mot-*ements of the handles.

To effect the electrical tripping of the switches, the latches are ormay be provided with reaim'ardly-extended portions 24 and Q-P which areadapted to be disposed over and in position to be engaged and raised bythe tripping plates 13 and 13" whereby to effect the depression of thenotched portions of the latches and the release of the levers 1t and1st. Said rearwardly extended por tions of the latches may be providedwith transversely-extended pins 25 and 25 by which the latches may beengaged and raised manually, whereby to permit the switches to be openedmanually. Said pins 25 and 25" are also arranged to perform certainfunctions in connection with the interlocking means as is hereinafterset forth.

Said handles 20 and 20" are adapted to be locked in vertical orswitch-closed positions by suitable means as the latches QT and 27. Saidlatches are or may be pivoted to the face plates and are adapted toengage suitable projections as pins 28 and 28 extended between andsecured to the spaced arms of said handles. The forward ends of saidlatches are adapted to extend forwardly and in front of said handleswhereby to perinit the extended ends thereof to be engaged manuallythereby to release the handles and permit them to be moved outwardly.The above described arrangement forms means by which the switches may beopened independently of corresponding movements of the handles; and thehandles are adapted to be independently moved to switch-open position tore-engage their respective mechamsms.

The interlocking mechanism is arranged, when both switches are open, tolock the mechanism of the running switch against closing and permit thestarting switch to be free to close. The interlocking mechanism is alsoso arranged that when the starting switch is closed the running switchis free to be closed but, before the running switch can be moved intoclosed position, the inter locking mechanism is arranged to be actuatedto trip open the starting switch so that both switches can not be closedat the same time, neither can the running switch be closed before thestarting switch. The in terlocking mechanism is also arranged to preventthe closing of the starting switch when the running switch is closed:

The interlocking mechanism includes a stud shaft journaled in a hub 36,which hub is extended toward the running switch and is or may be securedto or formed integrally with the supporting frame 37, which latter is ormay be secured to the face plate 10 in a suitable manner. The runningswitch is also provided with a similar stud shaft 35 which is journalledin a hub 36 carried by the supporting frame 37, which frame is or may besecured in any suitable manner to the face plate 10 of the runningswitch. Said stud shafts and 35 are adapted to be directed toward eachother and approximately in axial alignment. The ends of said shafts 35and may be flattened to receive the yokes 3S and 38 which yokes may bepivotally connected by suitable means as the pins 39 and 39 to theflattened portions of said shafts. Said yolzes are or may be formed withslots 40 and 10 &

therein in which a connecting bar 41 may be received and saidbar may be.pivotally connected to said yolnes by suitable means as the pins 42 and42 aind'in such a manner that said bar is pivotal in said yoikes at ri tangles to the pivoted connection of said yo es with their respectiveshafts. The erran ementis adapted to be such that a flcxi'le connectionis or may be formed between said shafts and 35 and a universal joint isprovided between said bar 41 and the shafts 35 and 35. An end of therunning shaft 35 is or may be disposed within the supporting bracket 37and may have an arm 43 fixed thereto and said arm may be formed orprovided with a suitable lateral extension, as the pin'44, at the endthereof.

Said. arm 43 may also be provided with an extension 45 between which anda fixed part of the face plate, as said bracket 37, a retractile spring45 is or may be connected. Said spring is adapted to bias theinterlocking mechanism yieldingly into a position in which therunningswitch is normally locked against closing and the starting switchis free to be closed.

The lever 14 of the running switch is or may be formed or provided witha bracket 47 which extends laterally to clear one of the arms of theoperating handle 20 and thence inwardly to provide the extension 48.- Acam link 49 is pivoted to said ex-' tension 48 and the inner end thereofis or may be formed with a slot 50 therein in which said pin 44 isadapted to be received, whereby to form a loose connection with said arm43. Said link 49 is or may be formed with an upper cam face 51 which isadapted to engage the latch pin 25 under certain conditions.

When theinterlocking mechanism is so arranged that the arm 43 oftheconnecting shaft is held and-maintained in the position illustratedin 3, the cam link 49 1 is adapted to be held in such a position as tomaintain the latch 22 in raised position with its notched forwardportion free from engagement with the latch roller 18 of the switchmechanism for the running switch. As thus arranged, the operating handle20* for the running switch is disconnected from the switch mechanism.The handlemay move between the openand closed positions, the latch pin25 during this movement traveling over the cam face 51 of the cam link,but this movement is without effect upon the switches the operatinghandle is disconnected from the switch mechanism. 7 When, howevensaidarm 43 of the interlocking sh'aftis moved to some depressed. position asthat-illustrated in Fig. 6, and held in such position, the control link'49 is moved downward and away from engagement with the latch pin 25' ofthe latch 22. Consequently,.said latch is free ism is correspondinglymoved and the runnziug switch may be closed. This closing movement ofthe switch however is permitted only after the starting switch has beenoperated. For this purpose, the operating stud shaft 35 of the startingswitch 1s,or may be provided with an arm 55 secured'to that end thereofwithin the supporting frame 37 and said arm is or may be formed orprovided with a lateral extension as the pin 56. In the normaldisposition of the switch mechanism or with both switches open and withthe running switch locked against closing, the relative angular positionof said arms 55 and 43 of the starting and running switches is or may beas illustrated in Figs. 2 and 3. Said arm 55, and consequently theinterlocking shaft, is adapted to be locked against rotation in theposition illustrated in Fig. 2 by suitable means as a latch 57. beformed or provided with a notched portion 58 in which the pin 56 of saidarm is adapted to be received and the construction of said notchedportion is or may be such as to prevent angular movement of said arm 55an consequently said shaft in either direction. A spring 59 is or may bearranged to engage said latch 57 and a fixed abutment, as the face plate10, whereby to maintain said latch yieldingly in looking position. v

As thus arranged, the starting switch is free to be opened and closed.As the starting switch is moved toward closed position means areprovided to move said locking latch 57 away from locking engagement withthe arm 55 and effect the actuation of the interlocking mechanism toremove the lock on the running switch. For this purpose said latch 57 isor may be disposed adjacent one of the links 16. Said latch may beprovided with a sloping or cam-faced forward portion 60 and the pin 61which connects said links 16 with the lever 14 may be arranged to engagesaid forward portion of said latch, as the starting switch is movedtowards closed position, and depress said latch away from lockingengagement with the arm Upon a further movement of the switch mechanismtowards closed position, said pin 61 is or may be also arranged toengage said arm and move said arm and correspondingly rotate theinterlocking shaft whereby to remove the arm 43 associated with therunning switch into some position as that indicated in Fig. 6 andthereby remove the lock on the running switch. The relation between thepin 61 and the latch 57 and arm 55 is or may be such ;that the abovedescribed action does Said latch may not take place until the startingswitch is substant-iall in closed position.

ll ith the interlocking mechanism as thus arranged the running switch isfree to be moved into closed position. The interlocking meehanisn'i isarranged to be actuated during the part of the closing morement oi therzu'ming switch to open the starting switch and before the runningswitch is moved into actual switch-closed position. This operation ma beeffected in a number of ways. The proportions and arrangement oi thecontrol link it) and the arm and pin ociated with the running switch besuch that when the runnin moved in a closing dire; .c the cotto -.1 ofthe slot 50 in said link 49 is moved into engagement with the pin a anda further movement the runot' sait ning handle serves to move l arm androtate the interlocking shatt to etliect the tripping ot' the startingswitch as is hereinafter explained. For certain purposes, however, itmay be desirable to so arrange the mechanism that the cam face ot' thebracket -l-T is arranged to engage the pin L-l o1" said arm a3 andeffect the rotation of said arm as illustrated in 8, the length of theslot in said cam link 49 being such as to permit this movement. Therotation of said arm it-3 and interlocking shaft to effect the trip wingof the startin." .r L C switch is arranged to take place during thefirst part of the closing movement of the running switch and before therunning switch has been moved to any substantial degree toward switchclosing position.

The tripping ot' the starting switch by the movement of the interlockingshaft is or may be controlled by a lever 70 which is or may be pivotedat its inner end to the face plate 10 of the starting switch. Said lever'70 or ma be disposed beneath the pin 25 of the latch 2i and is or mavbe formed with an upper cam face '71 which is adapted to engage said pinwhen the lever is moved upwardly and raise and eiiect the disengagementof said latch 2% with the cam roller 18 of the switch mechanism, wherebyto cause said mechanism to move to open position. Eiaid lever 70 is ormay be arranged to be controlled bv the interlocking shaft and the armthereof. For this purpose said arm may be formed or provided with alateral extension as the pin 73, which pin is or may be disposed beneathsaid lever in a position to engage a cam face T-tof said lever. Said camface it is or may be so arranged, that when said arm is actuated bv thestarting switch to release the lock on the running switch no substantialamount of movement is imparted by said pin 73 to said lever. Said camtaco however. is or may be provided *ith a contiguous face 75 ofincreased declination and so arranged that when said interlocking shaftand arm 55 are rotated by the running switch, the pin 73 of said arm isadapted to engage said cam face 75 and move the lever 70 upward. Thismovement of the latch serves to raise the latch Q-l and therebydisconnect the switch mechanism including the lever It from theoperating handle 20 and consequently said switch mechanism is free tomove into open position.

The shape and arrangement of the upper cam 'lac' 71 ot said lever 70 isor they be such that when the running switch is in open position thestarting handle 20 may be moved between open and closed positFoaswithout eliciting the release of the latch "from the switch mechani taid lever '50 is adapted to extend forwardly of the lace plate 10 and inposition wherein may be readilv enga ed by the hand and rai ed ther byto trip out the starting h it desired.

the mechanism is thus arranged, it is apparent that when both switchesare d the rm'ining switch is locked against and when the starting switchis closed the initial closing movement of the running switch serves totrip out the starting switch so that but one switch can be closed at atime and the order of operation or the .witches is predetermined.

The structure may be otherwise modified without departing from thespirit of the invention.

I claim:

1. The combination of two independentelectric switch mec ianisms eachhaving an actuating member and means to lock the actuating member to theswitch mechanism, and interlocking mechanism controlling said switchmechanisms, said interlocking mechanism including means to govern thelocking means of said switch mechanisms.

2. The combination of two independent electric switch mechanisms eachhaving an actuating member and means to lock the actuating member to theswitch mechanism. and interlocking mechanism controlling said switchmechanisms, said interlocking mechanism including means to govern thelocking means of said switch mechanisms and constructed and arrangednormally to hold one of said locking means tree from locking position.

The combination of two independent electric switch mechanisms eachhaving an actuating member and means to lock the actuating member to theswitch mechanism, and interlocking mechanism controlling said switchmechanisms, said interlocking mechanism including means to govern thelocking means ot said switch mechanisms and constructed and arrangedalternately to hold the locking means of one switch mechanism switchmechanism is in closed position.

t. The combination of a starting switch anda running switch, each havingswitch mechanism and an actuating member therefor, means to connect saidactuating members relcaslngly with their respective switch mechanisms,and interlocking mechanism governing said switches arranged to actuatethe disconnecting means of one switch and permit the respectiveactuatingmember to be moved between open and closed positions free from itsswitch mechanism.

5. The combination of a starting switch and a running switch, eachhaving switch mechanism and an actuating member ther for, means toconnect said actuating mem bers releasingly with their respective switchmechanisms, and interlocking mechanism arranged to govern said switchmechanisms independently of said actuating members, whereby to permitsaid actuating members to he moved between switch open and closedpositions free from said switch mechanisms.

6. The combination of a starting switch and a running switch each havingswitch mechanism and actuating members, means to connect said actuatingmembers releasingly with their respective switch mechanisms, andinterlocking mechanism arranged to governsaid connecting means andpermit said actuating members to be moved between switch open and closedpositions free from said switch mechanisms.

The combination of two switch mechanisms each having an actuating memberand a latch governing the connection be tween the switch mechanism andactuating member, and interlocking mechanism governing said latchesarranged normally to hold one latch in a release position, whereby tofree an actuating member from connection with its switch mechanism.

8. The combination of two switch mechani-sms each having an actuatingmember and a latch governing the connection between the switch mechanismand actuating member, and interlocking mechanism governing said latchesarranged normally to hold one latch in a release position, whereby tofree an actuating member from connection with its switch mechanism, andmeans to actuate said interlocking mechanism byone switch mechanism inits movement toward switch closed position to release the latch of theother switch mechanism and effect the operative connection between saidswitch mechanism and its actuating member.

9. The combination of two switch mechanisms each having an actuatingmember and a latch governing the connection between the switch mechanismand actuating member, and interlocking mechanism governing said latcharranged normally to hold one latch in an unlocked position, whereby tofree an actuating member from connection vith its switch 1 echanism,means to actuate said interlocking mechanism by one switch mechanism inits movement toward switclrclosed position to release the latch of theother switch mechanism and cilect the operative connection between saidother switch mechanism and its actuating member, and means actuated bysaid other switch mechanism to actuate said interlocking mechanism andtrip the latch of said first switch mechanisms, whereby to open saidfirst mechanism.

The combination of starting and running switch mechanisms each having anactu-ating member and a latch connecting the actuating member with itsswitch mechanism and interlocking mechanism arranged to govern theoperation of said switch mechanisms, said interlocking mechanism including a movable member disposed to engage and raise said latches intoan actuating member release position, and means to govern the order ofoperation of said movable members.

11. The combination of starting and. running switch mechanisms eachhaving an actuating member and a latch connecting the actuating memberwith its switch mechanism, and interlocking mechanism arranged to governthe operation of said switch mechanisms, said interlocking mechanismincluding movable members disposed to engage and raise said latches intoactuating-member release-positions, and means to govern the order ofoperation of said movable members including a mechanical connectionbetween said movable members.

12. The combination of starting and running switch mechanisms eachhaving an actuating member and a latch connecting the actuating memberwith its switch mechanism, and interlocking mechanism arranged to governthe operation of said switch mechanisms, said interlocking mechanismincluding movable members disposed to engage and raise said latches intoactuating-member release-positions, and means to govern the order ofoperation of said movable members including a shaft connecting saidmovable members arranged for actuation by said starting switchmechanism, and means governed by said starting switch mechanism to locksaid shaft against operation.

13. The combination of starting and run ning switch mechanisms eachhaving an actuating member and a latch releasingly connecting theactuating members with their respective switch mechanisms, andinterlocking mechanisms arranged to govern the operation of said switchmechanisms, said interlocking mechanism including a shaft extendedbetween said switch mechanisms, arms fixed to said shaft disposed togovern the operation of said latches, the arm aslal'll sociated withsaid starting switch mechanism disposed to be engaged by said meclranism in its closing movement, whereby to raise the latch of the runningswitch mechanism, and means to lock said arm and said shaft againstmovement, said locking means arranged and disposed to be operated bysaid starting switch mechanism to release the lock on said shaft.

1*}; The combination of starting and running switch mechanisms eachhaving an actuating member and a latch re casingly connecting theactuating: members with their respective switch mechanisms, andinterlocking mechanism arranged to govern the operation of said switchmechanisms, said interlocking mechanisms including a shaft extendedbetween said switch mechanisms, arms fixed to said shaft disposed togovern the operation of said latches, the arm associated with saidstarting switch mechanism disposed to be engaged by said mechanism inits closing movement, whereby to raise the latch of the running switchmechanism, means to lock said arm and said shaft against movement. saidlocking means arranged and disposed to be operated by said startingswitch mechanism to release the lock on said shaft, and means actuatedby said running switch mechanisms to operate said released shaft andraise the latch of said starting switch mechanism.

15. The combination of starting and run ning switch mechanisms eachhaving an actuating member and latch connecting the actuating memberwith its switch mechanism, and interlocking mechanism arranged to governthe operation of said switch mechanisms. said interlocking mechanismincluding a shaft extended between said switch mechanisms arranged to beactuated by said switch mechanisms. an arm fixed to said shaft andassociated with the running switch mechanism, and a link pivotallyconnected with said running switch mechanism and having a looseconnection with said arm, said link disposed to engage and control theoperation of the latch of said running switch mechanism.

16. The combination of starting and run ning switch mechanisms eachhaving an actuating member and a latch connecting the actuating memberwith its switch mecha nism, and interlocking mechanism arranged togovern the operation of said switch mechanisms, said interlockingmechanism including a shaft extended between said switch mechanismsarranged to be actuated by said switch mechanisms, an arm fixed to saidshaft and associated with the running switch mechanism, and a cam-linkpivotally connected with said running switch mecha nism and having aloose connection with said arm, said link having a cam face arranged toengage the latch of said running switch mechanism and raise it fromlocking connection between said mechanism and its actuating member.

17. The combination of starting and running switch mechanism each havinga pivoted lever and actuating member and a latch pivotally carried bythe actuating member arranged releasingly to connect the lever andactuating member for conjoint movement, and interlocking mechanismarranged to govern the operation of said switch mechanisms including ashaft extended between said mechanisms and biased toward position tolock the running switch mechanism against closing, an arm fixed to saidshaft and associated with said running switch mechanism, a cam-linkpivoted to the lever of said running switch and having loose connectionwith said arm, said lin having a cam face engageable with the latch ofsaid mechanism to raise and hold it out of operative position, an armfixed to said shaft and associated with said starting switch mechanismand arranged to govern the latch thereof, said arm disposed in the pathof movement of the starting switch mechanism to be actuated thereby androtate said shaft against the bias thereof and condition the runningswitch mechanism for closing, means to lock said arm and shaft againstoperation by said running switch mechanism in the open position of saidstarting switch mechanism. said locking means arranged and disposed tobe operated by said starting switch mechanism to release said arms andshaft prior to the actuation of said arm and shaft by the startingswitch mechanism, and said running switch mechanism subsequentlyarranged in the closing movement thereof to actuate said shaft and tripthe latch of the starting switch mechanism prior to the complete closingof the running switch mechanism.

18. The combination of two switch mechanisms each having means to lockits mechanism in switch-closed position, and means operated by theclosing movement of one switch mechanism, and prior to the comple tionof such closing movement, to release the lock on the other mechanism,whereby to effect the opening movementof said other mechanism.

In testimony whereof, I have signed my name to this specification.

CHESTER D. AINSVORTH.

